During the nights of the long winter seasons on Saturn, on the contrary, the surface of the rings turned towards the hemisphere undergoing winter, receives no light from the Sun, and is invisible, or very nearly so, except towards morning and evening, when it may be faintly illuminated by the secondary light which it receives from the illuminated globe of Saturn. Although dark and invisible, the rings may make their form apparent at night by the absence of stars from the region which they occupy in the sky. Again, in other seasons, the days present very curious phenomena. In consequence of the diurnal rotation of the planet, the Sun seems to move in circular arcs, which, owing to the inclination of Saturn's axis, are more or less elevated above its horizon, according to the position of the planet in its orbit. As such arcs described by the Sun in the sky of Saturn are liable to encounter the rings, the Sun in passing behind them becomes eclipsed. It must be a magnificent spectacle to witness the gradual disappearance of the fiery globe behind the outer ring, and its early reappearance, but for a moment only, through the narrow gap of the principal division; to see it vanish again behind the middle ring, to reappear a little later through the semi-transparent dusky ring, but very faint and red colored at first; and then, gradually brighten up, and finally emerge in all its beauty from the inner edge of the dusky ring. It is in latitude 23° that the rings produce the most prolonged eclipses of the Sun. During a period equivalent to ten of our terrestrial years, such eclipses continually succeed each other with but very short periods of interruption; and even during a long series of rotations of Saturn, the Sun remains completely invisible in those regions where the apparent arcs which it describes coincide with the arcs of the rings. In neighboring latitudes, the eclipses of the Sun, although still frequent, would have a shorter and shorter duration as the observer should travel north or south. These eclipses of the Sun must produce a partial darkness of the regions involved in the shadow of the rings, which may be compared to the darkness produced on our globe by a total eclipse of the Sun. The frequent recurrence of these eclipses, and their comparatively long duration in some regions, must still further reduce the duration of the short Saturnian days.